Bone Abstracts

Background: Eosinophilic granuloma (EG) typically affects children in the first two decades of life, mainly involving vertebrae and long bones. This study presents the first –to the best of our knowledge - case of a unifocal EG of the femur, successfully treated with percutaneous image-guided radiofrequency ablation (RFA), which was monitored pre- and post-ablation with MRI-scans to validate the efficacy of this method.

Presenting problem: A 16-year-old boy was referred reporting gradually increasing pain in his right femur with an onset of approximately 2 months. Plain radiographs, CT- and MRI-scans, revealed a large lytic lesion in the femoral diaphysis with periosteal reaction without extension to the adjacent soft tissues. C-arm guided core needle biopsy performed with an 8 mm trocard under general anesthesia set the diagnosis of EG. Further imaging (radiographs and Tc99 bone scan) confirmed its unifocal type.

Clinical management: RFA took place in the CT suite room under general anesthesia. A thin biopsy needle was initially introduced through the thickened femoral cortex via the biopsy track. A 10 cm, 11 gauge plain electrode access system (RITA medical system) was used. The RFA procedure initiated following confirmation that the tip of the plain electrode was placed at the center of the lesion. The tip was heated up to 90–94 °C for 8 min. After a cooling period, the electrode, the probe and the canula were safely retracted. The patient reported immediate pain relief and was discharged the day after. He was advised to walk without bearing weight with the use of two crutches for one month. He underwent MRI-scans at 3, 6, 12, 18, 24 and 36 months after the RFA, confirming the complete necrosis of the EG and the subsequent focal regenerative procedure. He is currently symptoms-free, able to full-weight bearing and actively participating in athletic activities.

Discussion: Three more patients (English literature) suffering from EG were successfully treated with RFA. Our study confirmed the efficacy of the method by imaging studies as well. RFA seems to be a safe, simple and efficient method for the treatment of unifocal EG, providing fast relief from symptoms and significantly decreased morbidity.

Disclosure: The authors declared no competing interests.